Which substance should a student add to acidic soil to raise its pH?
Answer and explanation
Correct answer: Slaked lime, Ca(OH)₂
The governing concept is acid-base neutralisation and the pH scale. Acidic soil has excess acidity, so a suitable basic substance is added to react with and reduce the acid concentration. Slaked lime, Ca(OH)₂, is a base and therefore raises the soil pH; option A is correct. Hydrochloric acid, vinegar, and lemon juice are acidic and would lower the pH further.
Frequently asked questions
What is the correct answer to this question?
Slaked lime, Ca(OH)₂
Why is this the correct answer?
The governing concept is acid-base neutralisation and the pH scale. Acidic soil has excess acidity, so a suitable basic substance is added to react with and reduce the acid concentration. Slaked lime, Ca(OH)₂, is a base and therefore raises the soil pH; option A is correct. Hydrochloric acid, vinegar, and lemon juice are acidic and would lower the pH further.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
